Performance of rhesus monkeys on selected laboratory tasks presented before and after a large single dose of whole-body X radiation.

Abstract

Sixteen rhesus monkeys (Macaca mulata) were trained for a year on a series of behavioral tests. These tests included food-rewarded object displacement tasks and manipulation tasks (4 of which did not involve food rewards). After the initial training all of the tasks were presented to each animal in a period of massed training. Ten of the animals received 400 r. irradiation with X-rays and the remaining six animals were sham-irradiated. Following the period of radiation all animals were again trained on all previously administered behavioral tasks during a period of 80 days after dosage ended. Transitory changes were found in the performance of the irradiated animals on manipulatory tasks following the period of irradiation, but the performance of the animals in both the experimental and control groups remained high and unchanged in the period following radiation. The results are contrasted with findings obtained in a parallel study employing direct naturalistic observations of the performance of the animals in this experiment.